Shifting paradigms in 30,427 surgical colorectal cancer cases (2008–2023): the impact of endoscopic screening on caseload complexity and the value of minimally invasive quality

Abstract Background While global registries report a rising incidence of early-onset colorectal cancer (EOCRC), the impact of widespread screening and endoscopic therapeutics on the case-mix of major surgical centers remains undercharacterized. We aimed to quantify the 16-year evolution of surgical demographics, pathological profiles, and quality metrics to delineate how modern practice reshapes surgical volume and outcomes. Methods We conducted a retrospective analysis of 30,427 consecutive patients undergoing colorectal cancer (CRC) resection at Fudan University Shanghai Cancer Center from 2008 to 2023. The cohort was stratified into three eras: Era 1 (Open-predominant, 2008–2012), Era 2 (Transitional, 2013–2017), and Era 3 (Minimally Invasive-predominant, 2018–2023). Trends in demographics, tumor morphology, stage distribution, lymph node yield, and 5-year overall survival (OS) were analyzed. Results Contrary to global incidence trends, the proportion of surgically managed EOCRC (< 50 years) declined from 24.8% in 2008 to 14.6% in 2023, while patients aged ≥ 65 years increased from 27.4 to 39.4% ( P < 0.001). A pattern consistent with a hypothesized “endoscopic filtering effect” was observed: the proportion of surgical Stage 0–I cases contracted from 20.3 to 12.4%, while adenoma with high-grade intraepithelial neoplasia (HGIN) rose dramatically from 1.5 to 12.3%. Mean tumor diameter exhibited a “J-shaped” trajectory: decreasing from 4.20 cm in 2012 to a nadir of 3.80 cm in 2014, before rebounding to 4.20 cm by 2023. Surgically, laparoscopy adoption surged from 0.2 to 64.5%. This transition was accompanied by a steady increase in mean lymph node yield, rising from 15.4 in Era 1 to 16.9 in Era 3 ( P < 0.001). In 2023, the mean lymph node yield in the laparoscopic group (16.3 ± 6.8) was numerically superior to the open surgery group (15.6 ± 7.7; P = 0.067). Regarding prognosis, 5-year OS peaked during the transitional period (Era 2: 75.9%). Although OS declined in Era 3 (69.5%) concurrent with the shift toward an older and more complex case-mix, outcomes remained robust and comparable to the historical baseline (Era 1: 73.0%). Conclusions The landscape of surgical CRC has shifted toward an older population with more complex, locally advanced disease, a pattern consistent with upstream endoscopic diversion of early-stage cases. Despite this increased demographic burden, the maturation of minimally invasive techniques has maintained high-quality oncological clearance, as evidenced by improving lymph node yield and declining circumferential resection margin (CRM) positivity rates. After adjusting for age, sex, stage, tumor location, and surgical approach, survival outcomes in the most recent era were comparable to the historical baseline (HR = 1.049, 95% CI 0.976–1.128, P = 0.194). Graphical abstract